1. Field of the Invention
The present invention relates generally to the ironing and smoothing of fabrics and clothing using hand operated flatirons, and more specifically to a cover which is removably attachable to the sole plate of such irons to protect materials being ironed from scorching, burning, or polishing during the ironing process. The cover is formed of a thin, planar polytetrafluoroethylene plastic sheet (e. g,, Teflon, tm) and conforms to the configuration of the specific iron sole plate to which it is removably attached by becoming soft and pliable due to the heat from the iron. Steam holes generally conforming to the typical pattern of steam vents in the sole plate of an iron are also provided through the thin sheet.
2. Description of the Prior Art
While the advent of synthetic fabrics and advances in manufacturing techniques for natural fabrics has resulted in clothing and other fabrics which are easier to care for than many fabrics in the past, the need to iron clothing and other fabrics to smooth and eliminate wrinkles, still exists. Similarly, advances in the art of hand held fabric pressing irons have also been achieved, which make the task easier.
Nevertheless, ironing clothing and other fabrics is a tiresome task, due to the necessary mass of such irons required to press out wrinkles in the fabric, and the friction between the sole plate of the iron and the underlying fabric. Iron manufacturers are well aware of this, and have made numerous attempts to manufacture irons which are easier to use, in order to develop more sales. While little can be done to remove the required mass for proper ironing, various improvements have been made in the reduction of friction between the sole plate and the underlying article being ironed, as by providing polished sole plates and plates coated with a low friction plastic material of some sort, such as a polytetrafluroethylene (PTFE, which abbreviation will be used throughout the remainder of the present disclosure) plastic compound, an example of which is sold under the trademark name Teflon by the DuPont Corporation. These plastic coatings of the metal iron sole plate also provide an additional advantage, in that they tend to provide more even heat distribution to reduce the likelihood of scorching or burning the fabric being ironed.
However, these PTFE plastics tend to be relatively soft, and will be abraded or worn away after some period of time. This leaves the bare metal sole plate exposed, with the disadvantages of such noted above. In fact, it may take a user some time to adjust to the different characteristics of the iron with the metal sole plate exposed, as opposed to a sole plate coated with PTFE. Also, many less expensive irons are not provided with a PTFE coating on the sole plate, for reasons of economy during manufacture.
Accordingly, a need will be seen for a removably attachable cover for hand held fabric pressing irons, which may be installed over a bare metal sole plate or over a previously plastic coated sole plate. The cover is formed of a thin sheet of PTFE plastic material, and is removably attachable to the iron. The very thin, planar sheet is heated by the iron, which causes the sheet to become pliable and to conform to the contours of the iron. Thus, only one size, or at the most a very few sizes and configurations, of such PTFE sheets need be provided, as they will conform to the specific shape of the iron (standard, smaller travel iron, etc.) to which they are secured. A plurality of steam vent holes should also be provided through the sheet, preferably in the general pattern of steam holes conventionally provided in the sole plate of steam irons. Such an iron cover may be installed to replace the worn plastic coating on an iron, or to provide such a coating for an iron not previously provided with such. The cover sheet may be removed and/or replaced as needed, serving to preclude or reduce the scorching, burning, snagging, and polishing of fabric materials being ironed. A discussion of such iron sole plate plastic covers which are known to the present inventors, is provided below.
U.S. Pat. No. 2,458,530 issued on Jan. 11, 1949 to David Resnick describes a Combing And Brushing Attachment For Sadirons, comprising an open rigid plate having plural transverse comb and/or brush elements extending across the bottom opening. This of course teaches away from the present smooth, thin, and resilient cover which covers the entire sole plate, with the exception of steam holes.
U.S. Pat. No. 3,142,916 issued on Aug. 4, 1964 to Sidney Jacobson describes an Accessory For Garment Steaming Devices, wherein a perforated metal plate is coated with a PTFE plastic on its underside. This composite plate is then removably secured to an iron, with the PTFE providing the advantages known in the use of such material. Jacobson, however, requires that the PTFE material be bonded to a rigid metal plate, rather than providing a thin sheet of PTFE material alone, as in the present invention. Manufacture of the present sole plate cover is facilitated also, as no separate metal plate and bonding step need be provided.
U.S. Pat. No. 3,407,521 issued on Oct. 29, 1968 to William A. English describes a Steam Iron having a slightly upwardly inclined nose or toe area of the sole plate, serving to concentrate weight in that area when the iron is tilted forwardly. No particular coating or removable covering is disclosed for the sole plate of the iron.
U.S. Pat. No. 3,905,138 issued on Sep. 16, 1975 to Antonio Abolafia describes a Steam Iron Shoe, comprising a metal plate and a PTFE coating sandwiching a fabric layer therebetween. The result is a rigid assembly, which must be specially formed for different iron sole plate configurations. The Abolafia plate attachment more closely resembles the Jacobson plate attachment discussed further above, than the present plate attachment formed entirely of a thin PTFE sheet. Conventional coil springs are used to secure the Abolafia plate attachment to the sole plate, as in the case of Jacobson and Resnick, as well as the present cover.
U.S. Pat. No. 3,930,325 issued on Jan. 6, 1976 to Robert L. Schaeffer et al. describes Steam Iron Soleplate Construction with the sole plate formed from relatively thin sheet material, rather than cast. Schaeffer et al. note that such material may be coated with PTFE, as is known in the art, but are silent regarding any PTFE cover which may be removably secured to the sole plate.
U.S. Pat. No. 4,209,921 issued on Jul. 1, 1980 to Josef Kochauf describes a Flat Iron Foil formed of a thicker sheet of PTFE than that used in the present invention. The Kochauf PTFE has a plurality of ridges along the upper surface, to space the steam vent holes from the bottom of the iron sole plate. This is needed, as Kochauf does not particularly align his steam holes with those in the iron sole plate, as noted in column 3, lines 11-13 of his patent. Without the ribs, the extremely small surface area of each collar of the holes would produce significant localized pressure against the sole plate, thus blocking steam flow. In the present cover, a myriad of steam vent holes are provided through the thin sheet in a pattern generally aligned with the conventional steam hole pattern in the sole plate of an iron, so at least some of the holes in the cover will be generally aligned with the steam outlet holes in the sole plate of the iron. Also, as the Kochauf cover is spaced from the sole plate by the ribs and/or steam vent opening ridges, there is some question of even heat transfer due to the air gap between the iron sole plate and the PTFE cover. The present sole plate cover is formed as a uniform, flat, planar sheet devoid of protuberances, and is in continuous, unbroken contact with the iron sole plate when installed. Also, the Kochauf ribs and steam vent opening ridges would allow a relatively thin sheet of PTFE plastic material to collapse between those ribs and ridges when the weight of the iron was resting thereon, with the cover being compressed between the iron and the compliant underlying fabric material. This is even more true when the material is heated by the iron and/or steam and becomes relatively soft and pliable. The resulting collapse of the sheet between the ribs and vent opening ridges, would result in uneven pressure on the underlying clothing or other fabric material being ironed, and a relatively inefficient means of removing wrinkles and smoothing the fabric.
U.S. Pat. No. 4,642,922 issued on Feb. 17, 1987 to Giorgio Prudenziati describes a Removable Steam Iron Sole Plate comprising a specially formed iron having a sole plate with a shallow depression therein. A rigid perforated stainless steel plate is removably secured therein by screws. No PTFE coating, removable or otherwise, is disclosed.
U.S. Pat. No. 4,660,307 issued on Apr. 28, 1987 to John W. Fay describes a Cover For Film Irons, as used in adhesively attaching and heat shrinking plastic sheet (e.g., Monokote, tm) to model aircraft structures. The use of permanently bonded PTFE coatings to such irons is known, as shown in column 1, lines 16-19 of the patent, similar to bonding a PTFE film to conventional fabric irons. The Fay patent is directed to a fabric cover which is removably securable over the iron head, to preclude scratching the plastic sheet if the PTFE coating of the iron is damaged.
U.S. Pat. No. 4,665,637 issued on May 19, 1987 to Carolyn M. Kramer describes a Sole Plate Coating For A Fabric Pressing Device comprising a ceramic layer bonded to the metal sole plate of the iron. No PTFE material is disclosed, nor is the ceramic coating removable from the iron, as is the PTFE plastic sheet of the present invention.
U.S. Pat. No. 4,747,222 issued on May 31, 1988 to Gunther Riba describes a High-Pressure Steam Flatiron, with the primary object being an iron which is simpler and less expensive to produce. Accordingly, no PTFE or other coatings of the sole plate are disclosed by Riba.
U.S. Pat. No. 4,800,661 issued on Jan. 31, 1989 to Hiroshi Yamamoto et al. describes an Electric Iron having a PTFE coating on the sole plate thereof. The PTFE is adulterated with a metallic powder to reduce electrostatic differences between the sole plate and fabric being ironed, as well as to provide better heat transfer. A resin may also be added to provide a harder coating. Yamamoto et al. recognize that PTFE plastic will soften and be subject to greater wear when exposed to the heat of a typical iron, as noted in column 1, lines 26-36 and FIG. 6 of their disclosure. Their response is by means of altering the chemical structure of the PTFE coating on the sole plate, rather than making a separate and removable PTFE sheet for such sole plates, as provided by the present invention. It is desirable that the PTFE sheet of the present invention soften under heat to a certain degree, to conform to different iron sole plates.
U.S. Pat. No. 4,856,212 issued on Aug. 15, 1989 to Joseph Dikoff describes a Cordless Iron With High-Temperature, Non-Scorching Sole Plate Surface. The material used for the sole plate coating is a polyamide film provided by the DuPont Corporation under the trademark name, "Kapton." The material has somewhat more stable properties at high temperatures than does PTFE. Dikoff provides his coating as a thin film which is permanently bonded to the sole plate, rather than as a removable sheet, as in the present invention.
U.S. Pat. No. 5,164,244 issued on Nov. 17, 1992 to Henry Mattesky describes the Non-Staining Lubrication Of Laundry Iron Soles, wherein a fabric sheet impregnated with a silicone elastomer (not PTFE) is provided over which the hot iron is passed. Some friction reducing agent from the elastomer is transferred to the iron sole plate, enabling the iron to be passed more easily over articles being pressed. No removable PTFE sheet for the iron sole plate is provided by Mattesky.
U.S. Pat. No. 5,165,184 issued on Nov. 24, 1992 to Claudine Gardaz et al. describes an Ironing Device Sole-Plate With Coated Ribs, including a PTFE or enamel coating bonded to the sole plate. Additional reduction of friction and better bonding of the coating to the sole plate is claimed, but no disclosure is made of a removable PTFE sheet, as provided by the present invention. Moreover, the present removable PTFE sheet is smooth and planar in all directions, with the exception of steam vent holes, and contains no ribs or other protuberances.
Finally, U.S. Pat. No. 5,165,185 issued on Nov. 24, 1992 to Claudine Gardaz et al. describes an Ironing Device Sole-Plate With Resin Projections, comprising a series of spaced apart ribs extending from the PTFE coating bonded to the sole plate. The configuration is somewhat similar to the same patentee's '184 patent discussed immediately above, with the same advantages. There is some question, however, as to the smoothness of the pressing accomplished by using other than a perfectly smooth, planar pressing surface, as provided by the present iron sole plate removable PTFE sheet.
None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed.